2018 Theses Doctoral

Acute Effects of Resistance Exercise Intensity in a Depressed HIV Sample: The Exercise for People Who Are Immunocompromised (EPIC) Study

Nosrat, Sanaz

Introduction: In the US, Black/African Americans comprise the largest proportion of People Living with HIV (PLWH). Depressive symptoms and fatigue are highly prevalent among PLWH. Depressive symptoms are linked to progression of HIV disease, and fatigue is linked to severity of depressive symptoms. Resistance exercise is known to have psychological benefits in non-HIV depressed populations, and these benefits are hypothesized to be intensity-dependent. That is, moderate intensity exercise seems to stimulate better psychological outcomes compared to other exercise intensities. To date, no study has examined the acute psychological effects of resistance exercise intensity with depressed PLWH. Purpose: To test the acute effects of resistance exercise intensity on affect, perceived activation, and perceived distress among sedentary Black/African American PLWH who experience depressive symptoms. Methods: Twenty-five men and 17 women ages 24-66 (47.5±11.2) with a Center for Epidemiologic Studies Depression Scale score of ≥10 completed a battery of questionnaires and 10-repetition maximum (10-RM) muscular strength tests. Participants were randomized into a moderate intensity resistance exercise group (i.e., 70% of 10-RM), n=21, or vigorous intensity resistance exercise group (i.e., 100% of 10-RM), n=21. Both groups completed 3 sets of 10 repetitions for 5 exercises at the assigned intensity. Exercises include squat, chest press, lat pull-down, dumbbell shoulder press, and dumbbell biceps curl. Affect, perceived activation, and perceived distress were measured with the Feeling Scale, Felt Arousal Scale, and Subjective Units of Distress Scale, respectively. Measures were administered at PRE, MID, POST, at 15-minute DELAY, and at 30-minute DELAY. Changes were analyzed using repeated measures ANOVA, with Bonferroni adjustments for post-hoc analyses. Results: There were significant Time x Group interactions for affect (F=2.6, p=0.03, η2=0.1), and perceived distress (F=5.5, p<0.01, η2=0.1), and a main effect of Time for perceived activation (F=16.2, p<0.001, η2=0.3). In the moderate intensity group, affect improved PRE to POST (t=3.2, p<0.01, d=0.7), PRE to DELAY 15 (t=4.1, p<0.01, d=0.9), and PRE to DELAY 30 (t=4.1, p<0.001, d=0.7). In addition, perceived distress was reduced from PRE to MID (t=4.2, p<0.001, d=0.9), PRE to POST (t=5.5, p<0.001, d=1.2), PRE to DELAY 15 (t=5.6, p<0.001, d=1.2), and PRE to DELAY 30 (t=6.7, p<0.001, d=1.5). In the vigorous intensity group, affect declined PRE to MID (t=2.9, p<0.01, d=-0.6), while perceived distress improved PRE to DELAY 15 (t=4.8, p<0.001, d=1.0) and PRE to DELAY 30 (t=3.5, p<0.01, d=0.7). Perceived activation increased in both groups similarly PRE to MID (t=5.1, p<0.01, d=1.5), and PRE to POST (t=6.1, p<0.001, d=1.8). Conclusions: Results suggest that an acute bout of moderate intensity resistance exercise is more effective than vigorous intensity resistance exercise in improving affect, increasing energy, and reducing distress in depressed Black/African American PLWH. However, vigorous intensity resistance exercise also appears to have distress-reducing benefits, but this appears to only occur after exercise. These findings should be considered when prescribing exercise for depressive symptom management in this population.